This invention relates to a pumping assembly and, more particularly, to a pumping assembly which is driven by an electrical motor for pumping a liquid such as water.
Electrically driven water pumps for use in systems in which persons physically contact the water in the system, such as in swimming pools, household water systems, lavatories, and the like, present potential safety hazards. This is largely due to the fact that any breakdown in the internal insulation of the motor can impart an electrical voltage to the output shaft of the motor which can be conducted through the shaft, the mounting bracket for the pump and motor, and the pump housing to the electrical conductive water supply.
Although various techniques have been proposed to insulate the drive shaft from the water in the system, these solutions have been less than completely effective. Also, even in situations where the output shaft of the electrical motor is effectively insulated from the water, a hazard still exists due to the possibility of current leaking from the motor and through the pump housing to the water.
Although some recent designs have formed one or more of the components of such assemblies of a synthetic, dielectric material, such as plastic, the relatively intricate shape and arrangement of several of the individual components make it especially difficult to form them with the degree of precision that is required for optimum operation.